Two-way coal cutting bit



May 15, 1956 A. J. VOJTUSH TWO-WAY COAL CUTTING BIT Filed Nov. 19, 1954 1N VENTOR United States Patent 9 "ice TWO-WAY CGAL CUTTING BIT Andrew J. Vojtush, Clarksville, Pa.

Application November 19, 1954, Serial No. 462,398

6 Claims. (Cl. 26233) This invention relates to a mining machine chain bit.

A primary object of the invention is to provide a coal cutting bit which is readily attachable to a coal cutting chain and which is operative with equal efliciency upon travel of the chain in either of two opposed longitudinal directions.

A further object of the invention is to provide a coal cutting bit comprising a unitary steel block and which includes a chain lug engageable shank of rectangular cross section, and opposed cutting edges in symmetrical relation to the longitudinal axis of the said shank.

A still further object of the invention is to provide a coal cutting bit which is capable of resisting the force reaction when in use and which is capable of efiective cutting operations throughout its coal engageable vertical extent.

Other objects and advantages of the invention will become apparent in the course of the following detailed description, taken in connection with the accompanying drawing, wherein:

Fig. 1 is a side elevational view of the improved bit in accordance with a preferred structural embodiment thereof.

Fig. 2 is an end elevational view of the bit.

Fig. 3 is a top plan view of the improved bit.

Fig. 4 is a bottom plan view of the bit.

Referring now in detail to the drawing, the improved bit comprises a unitary steel block 19. The block includes an elongated chain lug engageable shank 11 which is rectangular in cross section. The shank is provided with a head forming the bit proper and which head includes a portion 12 bounded by opposed plane walls 13 which are parallel with corresponding Walls of the shank 11, opposite side walls 14 which are convex and which converge from bottom walls 15 to a cutting edge 16. The bottom walls 15 are relatively narrow and are normal to the opposite side walls of the shank 11.

The head further includes opposed wing portions 17 having bottom walls 18 in the plane of walls 15 and the wing portions further include opposite side walls 19 which are convex and which converge from the bottom walls to cutting edges 20 which are arcuate and extend from the bottom walls 18 to the opposed plane walls 13.

It is to be observed that the cutting edge 16 is in substantial spaced relation to the cutting edges 20. In order to provide cutting edges throughout the working dimenall 2,745,655 Patented May 15, 1956 sions of the bit, the walls 13 are provided with depressions 21 with resulting cutting edges 22 and the depressions further function to permit removal of cuttings.

The improved bit is readily attachable to standard chains upon insertion of the shank into a chain lug and contact of the walls 15 and 18 provide for automatic gaging of the bits.

It is to be particularly observed that the bit is symmetrical to the longitudinal axis of the shank 11 and is capable of use in either direction of travel of a chain without any adjustments thereof.

While I have disclosed my invention in accordance with a single specific structural embodiment thereof, such is to be considered as illustrative only, and not restrictive, the scope of the invention being defined in the subjoined claims.

What I claim and desire to secure by U. S. Letters Patent is:

l. A coal cutting bit comprising a unitary steel block including an elongated chain lug engageable shank and a cutting head, said head including opposed wing portions projecting from opposite edges of said shank at one end thereof, and a central body portion of greater dimensions lengthwise of said shank than said wing portions, and said first and second portions having cutting edges disposed in a longitudinal median plane of said shank with the cutting edge of the body portion displaced outwardly of said wing portions lengthwise of said shank.

2. The structure according to claim 1, wherein said shank is of rectangular cross section and having opposed side walls and opposed edge walls, said wing portions projecting outwardly from said edge walls and having plane base portions of the same width as said shank, said central body portion having plane base portions in the plane of said wing base portions and of a greater width than said shank, and said wing portions and said central body portion having side walls tapering toward each other and providing said cutting edges.

3. The structure according to claim 2, wherein said last side walls are convex.

4. The structure according to claim 2 wherein the end walls of said central body portion are in parallel spaced planes, and said walls each being provided with a depression adjacent the cutting edge of the central body portion and the walls of said depressions intersecting said end walls in the provision of additional cutting edges.

5. The structure according to claim 4, wherein the lower edges of said depressions are substantially at the juncture of said wing portions with said central body portion.

6. The structure according to claim 1, wherein the cutting edge on said central body portion is straight and the cutting edges on said wing portions being curved.

References Cited in the file of this patent UNITED STATES PATENTS 25,178 Crandall et a1 Aug. 23, 1859 FOREIGN PATENTS 217,274 Great Britain June 17, 1926 

